Problem: $ { \left[\begin{array}{rr}{-2} & {-2} \\ {1} & {2} \\ {1} & {1}\end{array}\right]-\left[\begin{array}{rr}{2} & {3} \\ {4} & {0} \\ {4} & {-2}\end{array}\right] = {?} } $
Answer: To find the difference of two matrices, subtract the corresponding items between each matrix. ${\left[\begin{array}{rr}{-2}-{2} & {-2}-{3} \\ {1}-{4} & {2}-{0} \\ {1}-{4} & {1}-{-2}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{-4} & {-5} \\ {-3} & {2} \\ {-3} & {3}\end{array}\right]}$